Innovations in enhancing adaptability and water productivity in tropical tuber crops

The tropical roots and tuber crops (R & T) consists of cassava, sweet potato, yams, elephant foot yam, taro, tannia and couple of minor tuber crops. Tropical tuber crops are the third most important food crops after cereals (rice, wheat etc) and pulses (pigeon pea, cow pea, green gram, black gram, chick pea, lentil etc.). These crops play a crucial role in providing food and nutritional security of the rural masses in Africa, Latin America and parts of Asia. In general tuber crops are grown in vulnerable agro climatic conditions and accounts to provide food for more than 500 million people across the globe. Cassava and sweet potato rank among the top 10 food crops produced in developing countries and contribute to about 6% of world's dietary calories. In India, tropical tubers are grown mostly in the states like Kerala, Tamil Nadu, Odisha, West Bengal, Andhra Pradesh, Bihar and North East covering 4.5% of the total area under vegetables with 5.7% of the total vegetable production. Low income farmers and most undernourished households in India depend on R & T crops. They value these crops for its high calorie value and stable yields under conditions in which other crops may fail. Genetic diversity of major tropical tuber crops also provides options for its diverse usage in "multicuisine", "nutrition", "feed", health care" and renewable resources of processing firms.

Most of these crops are bestowed with resilience to global warming and climate change. These crops have potential in reversing soil degradation. Genetic diversity of these crops, their wide adaptive nature advocates further innovations in enhancing adaptability. Such studies at ICAR-CTCRI resulted in developing improved varieties resilient to drought, salinity, water logging stresses, also with other marketable traits. Cassava already recognized as drought tolerant followed by yam. Further innovations led in developing robust plants. Varieties tolerant to higher temperature and CO2 concentration have also been identified. Outbreak of diseases and pests are addressed well in tropical tuber crops especially against cassava mosaic, taro leaf blight and sweet potato weevil. A global approach has enhanced allelic diversity in taro not only to cope up with the vulnerable leaf blight but also to help in shortening crop duration in meeting market demands. Water is a critical resource and vital for any production system including tuber crops. It needs to be tackled most specifically with water management practices. Rather it necessitates holistic management of all the vital components of production system viz., land, water, soil and genetic resources. Innovations in crop-water management would help to minimize water loss and thereby to assess water productivity. Recent studies indicate water productivity in cassava 8.3kg/m3, sweet potato 3.0 kg/m3, and elephant foot yam 2.5kg/m3 respectively. To maintain food and nutritional security under climatic crises, production system needs to be precised. It warrants ‘location and crop specific sensor based real-time water and agro inputs management practices’.